Well, The Ace Trainers appear focus on increasing exp earned by their Pokemon as well as increasing the Pokemon's offense.
Their advanced classes range from Chaser (Preventing the apposing pokemon from fleeing) to Underdog (Using less evolved Pokemon effectively) to Type/Stat (Which focus on using a particular type of pokemon, or boosting a single stat) to Tag Battlers (Two Pokemon for the price of one)
Plus a few others..
I'm on Breeder classes now.. The picture for the Chef advanced class is Brock.
“She'd become a governess. It was one of the few jobs a known lady could do. And she'd taken to it well. She'd sworn that if she did indeed ever find herself dancing on rooftops with chimney sweeps she'd beat herself to death with her own umbrella.”
― Hogfather